Type of Submission

Podium Presentation

Keywords

Metal on metal, finite element analysis, biomedical engineering, hip, hip replacement

Abstract

Metal on metal total hip replacements are a common procedure in which the hip joint is replaced with a metal stem, a metal femoral head and a metal socket, usually made of titanium or cobalt chromium. The stem has a tapered region (trunnion) where the femoral head is impacted onto. This creates what is known as the taper-trunnion interface within a hip implant. However, these hip implants seem to be very susceptible to fretting corrosion, where the corrosive fluid environment of the body accelerates the process of wear between two contact surfaces. Previous research has suggested that the design parameters of the taper and the trunnion could have a significant effect on the amount of fretting corrosion that is occurring at this interface. The parameter that showed the most promise is angular mismatch, or the difference in angles between the taper and the trunnion. Utilizing finite element analysis, we tested five different degrees of angular mismatch using a simplified model of the interface. We then recorded the maximum contact stresses along with the measured micro-motion of the trunnion against the taper. Finally we report and compare the difference in fretting work done between the different angular mismatched specimens.

Faculty Sponsor or Advisor’s Name

Dr. T.L. Norman and Dr. T.K. Fehring

Campus Venue

Stevens Student Center, Room 241

Location

Cedarville, OH

Start Date

4-1-2015 1:20 PM

End Date

4-1-2015 1:40 PM

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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Apr 1st, 1:20 PM Apr 1st, 1:40 PM

Finite Element Analysis (FEA) of the Taper-Trunnion Interface in a Metal on Metal Hip Implant

Cedarville, OH

Metal on metal total hip replacements are a common procedure in which the hip joint is replaced with a metal stem, a metal femoral head and a metal socket, usually made of titanium or cobalt chromium. The stem has a tapered region (trunnion) where the femoral head is impacted onto. This creates what is known as the taper-trunnion interface within a hip implant. However, these hip implants seem to be very susceptible to fretting corrosion, where the corrosive fluid environment of the body accelerates the process of wear between two contact surfaces. Previous research has suggested that the design parameters of the taper and the trunnion could have a significant effect on the amount of fretting corrosion that is occurring at this interface. The parameter that showed the most promise is angular mismatch, or the difference in angles between the taper and the trunnion. Utilizing finite element analysis, we tested five different degrees of angular mismatch using a simplified model of the interface. We then recorded the maximum contact stresses along with the measured micro-motion of the trunnion against the taper. Finally we report and compare the difference in fretting work done between the different angular mismatched specimens.

 

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